Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: boot hang on commit "PM / ACPI: Fix suspend/resume regression caused by cpuidle cleanup." | Date | Mon, 25 Jun 2012 22:45:07 +0200 |
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On Monday, June 25, 2012, Deepthi Dharwar wrote: > From: Deepthi Dharwar <deepthi@linux.vnet.ibm.com> > > Fix suspend/resume regression caused by cpuidle cleanup. > > Commit e978aa7d7d57d04eb5f88a7507c4fb98577def77 ( cpuidle: Move > dev->last_residency update to driver enter routine; remove dev->last_state) > was breaking suspend on laptops, as reported in the below link > - https://lkml.org/lkml/2011/11/11/164 > > This was fixed in commit 3439a8da16bcad6b0982ece938c9f8299bb53584 > (ACPI / cpuidle: Remove acpi_idle_suspend (to fix suspend regression) > by removing acpi_idle_suspend flag. > - https://lkml.org/lkml/2011/11/14/74 > > But this did fix did not work on all systems > as Suspend/resume regression was reported on Lenovo S10-3 > recently by Dave. > - https://lkml.org/lkml/2012/5/27/115 > It looked like with commit e978aa7d broke suspend and > with commit 3439a8da resume was not working with acpi_idle driver. > > This patch fixes the regression that caused this issue > in the first place. acpi_idle_suspend flag is essential on > some x86 systems to prevent the cpus from going to deeper C-states > when suspend is triggered ( commit b04e7bdb984 ) > So reverting the commit 3439a8da is essential. > > By default, irqs are disabled in cpu_idle arch specific call > and re-enabled in idle state return path . During suspend, > the acpi_idle_suspend flag is set, which > prevents the cpus from going to deeper idle states, > it is essential to enabling the irqs in this return path too. > > To address the suspend issue, > we were not re-enabling the interrupts while returning from > acpi_idle_enter_bm() routine if acpi_idle_suspend flag is set. > and this caused suspend failure. > > In addition to the above, to improve the readability of the code, > return of -ENIVAL is replaced with -EBUSY in acpi_idle_suspend > return path. Implying that the system is currently busy when suspend > is in progress, which prevents the cpus from entering deeper C-states. > > --- > This patch applies on 3.5-rc2 > > Reported-and-Tested-by: Dav Hansen <dave@linux.vnet.ibm.com> > Tested-by: Preeti Murthy <preeti@linux.vnet.ibm.com> > Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com> > Reviewed-by: Srivatsa S Bhat <srivatsa.bhat@linux.vnet.ibm.com> > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Looking good. I'll give it a bit of testing and put it into linux-next for a day or two to make sure nobody sees any more problems with it.
Thanks, Rafael
> --- > drivers/acpi/processor_idle.c | 32 ++++++++++++++++++++++++++++++-- > 1 files changed, 30 insertions(+), 2 deletions(-) > > diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c > index f3decb3..47a8caa 100644 > --- a/drivers/acpi/processor_idle.c > +++ b/drivers/acpi/processor_idle.c > @@ -224,6 +224,7 @@ static void lapic_timer_state_broadcast(struct acpi_processor *pr, > /* > * Suspend / resume control > */ > +static int acpi_idle_suspend; > static u32 saved_bm_rld; > > static void acpi_idle_bm_rld_save(void) > @@ -242,13 +243,21 @@ static void acpi_idle_bm_rld_restore(void) > > int acpi_processor_suspend(struct acpi_device * device, pm_message_t state) > { > + if (acpi_idle_suspend == 1) > + return 0; > + > acpi_idle_bm_rld_save(); > + acpi_idle_suspend = 1; > return 0; > } > > int acpi_processor_resume(struct acpi_device * device) > { > + if (acpi_idle_suspend == 0) > + return 0; > + > acpi_idle_bm_rld_restore(); > + acpi_idle_suspend = 0; > return 0; > } > > @@ -754,6 +763,12 @@ static int acpi_idle_enter_c1(struct cpuidle_device *dev, > > local_irq_disable(); > > + if (acpi_idle_suspend) { > + local_irq_enable(); > + cpu_relax(); > + return -EBUSY; > + } > + > lapic_timer_state_broadcast(pr, cx, 1); > kt1 = ktime_get_real(); > acpi_idle_do_entry(cx); > @@ -823,6 +838,12 @@ static int acpi_idle_enter_simple(struct cpuidle_device *dev, > > local_irq_disable(); > > + if (acpi_idle_suspend) { > + local_irq_enable(); > + cpu_relax(); > + return -EBUSY; > + } > + > if (cx->entry_method != ACPI_CSTATE_FFH) { > current_thread_info()->status &= ~TS_POLLING; > /* > @@ -907,14 +928,21 @@ static int acpi_idle_enter_bm(struct cpuidle_device *dev, > drv, drv->safe_state_index); > } else { > local_irq_disable(); > - acpi_safe_halt(); > + if (!acpi_idle_suspend) > + acpi_safe_halt(); > local_irq_enable(); > - return -EINVAL; > + return -EBUSY; > } > } > > local_irq_disable(); > > + if (acpi_idle_suspend) { > + local_irq_enable(); > + cpu_relax(); > + return -EBUSY; > + } > + > if (cx->entry_method != ACPI_CSTATE_FFH) { > current_thread_info()->status &= ~TS_POLLING; > /* > > Cheers, > Deepthi > > >
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